Tubular technology company Vallourec is pushing ahead with the commercial launch of its first large-scale underground hydrogen storage system this summer as it eyes growing demand in Europe and North America.

After building and commissioning its own demonstration site in 2023, France-based Vallourec is discussing designs for the potential deployment of the vertical storage solution, called Delphy, with 30–40 green hydrogen projects, hydrogen director Vincent Designolle told Hydrogen Economist in an interview.

“North America is an area of strong interest for us,” he said. “We have good leads in several states of the US, some related to the hydrogen hubs and some for projects that are independent from the hubs.”

In Europe, Vallourec recently formed a partnership with French green hydrogen project developer H2V. The firms have agreed to assess the potential to integrate the Delphy system into projects developed by H2V in the Marseille region.

Delphy is designed to store up to 100t of hydrogen in compressed gaseous form underground. The system requires an excavation of 5–10m in diameter, to a depth of up to 100m. “Delphy comes with a high capacity, but also a very, very high safety and minimal surface footprint compared to any conventional storage systems,” Designolle said.

On-site storage capacity at green hydrogen and consumption production facilities is a key target market for Delphy. In these applications, the ability to store large volumes will be critical. “Hydrogen has low density so it can be quite volumetric,” said Designolle.

A significant portion of the hydrogen production projects under development globally will require on-site storage, potentially generating “several tens of millions of euros” of revenue per project for Vallourec. Hydrogen storage will contribute to a target of growing the company’s new energies business to 10–15% of total EBITDA by 2030, rising to about a third by 2035.

Capital cost

With typical capital costs ranging from €20–50m for fully installed storage capacity, which can be customised for each project, the cost is “at parity or below” the capex required for equivalent on-site storage in tanks sitting above ground, Designolle said.

“North America is an area of strong interest for us” Designolle, Vallourec

Above-ground storage could require “a football field of storage tanks”, compared with the more compact underground solution offered by Delphy. The extra cost of excavation to install the Delphy system can be offset in areas such as instrumentation.

Designolle also highlighted Delphy’s ability to store compressed hydrogen in gaseous form, rather than the liquid form required by some other alternative storage solutions. The cost of liquefying the hydrogen to put into storage represents a loss if the hydrogen is not ultimately going to be used in liquid form further down the supply chain, he said.

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Author: Stuart Penson